13172521 has 8 divisors (see below), whose sum is σ = 13631688. Its totient is φ = 12720000.

The previous prime is 13172483. The next prime is 13172527. The reversal of 13172521 is 12527131.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 291600 + 12880921 = 540^2 + 3589^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 13172521 - 2¹¹ = 13170473 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13172492 and 13172501.

It is not an unprimeable number, because it can be changed into a prime (13172527) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2551 + ... + 5731.

It is an arithmetic number, because the mean of its divisors is an integer number (1703961).

Almost surely, 2^13172521 is an apocalyptic number.

It is an amenable number.

13172521 is a deficient number, since it is larger than the sum of its proper divisors (459167).

13172521 is a wasteful number, since it uses less digits than its factorization.

13172521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3323.

The product of its digits is 420, while the sum is 22.

The square root of 13172521 is about 3629.3967818358. The cubic root of 13172521 is about 236.1690412484.

Adding to 13172521 its reverse (12527131), we get a palindrome (25699652).

The spelling of 13172521 in words is "thirteen million, one hundred seventy-two thousand, five hundred twenty-one".